


Just Can't Hold It

by rubberupandmakeitstarker



Category: Iron Man (Movies), Marvel Cinematic Universe, Spider-Man - All Media Types, Spider-Man: Homecoming (2017)
Genre: Age Play, Age Regression/De-Aging, Awkward Sexual Situations, Bed-Wetting, Daddy Kink, Diapers, Dry Humping, Frottage, M/M, Mildly Dubious Consent, Omorashi, Orgasm Delay/Denial, Watersports, Wetting
Language: English
Status: Completed
Published: 2018-12-17
Updated: 2018-12-17
Packaged: 2019-09-20 19:01:54
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,751
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17028243
Author URL: https://archiveofourown.org/users/rubberupandmakeitstarker/pseuds/rubberupandmakeitstarker
Summary: Peter has always had an issue with age regression, for as long as Tony has known him. All he can assume is that it stems from losing his parents at such a young age, or may have even been triggered by the spider bite. He has never asked, and has only tried to be helpful when Peter goes into little space.Peter had gone for about a year without regressing. His 18th birthday has long passed, he and Tony have been dating for months, and just a few weeks ago, Peter moved in with Tony. That is when Peter started to regress again, but it isn’t manifesting in the way it used to. Before, Peter would just go nonverbal, or get overly shy and anxious, often accompanied with tears and requiring cuddles and a nap to snap out of it.This time, it’s not going away with some comfort or sleep, and the behavior is… more complicated.Peter has only regressed in one way that they can tell. He is still verbal; he is still emotionally well; he just… can’t seem to be able to stop wetting himself.





	Just Can't Hold It

**Author's Note:**

> All characters are 18+. I know nothing about age regression, so I’m sorry if I depicted it poorly. Read the tags, I do not fuck around in this baby.

Peter has always had an issue with age regression, for as long as Tony has known him. All he can assume is that it stems from losing his parents at such a young age, or may have even been triggered by the spider bite. He has never asked, and has only tried to be helpful when Peter goes into little space.

Peter had gone for about a year without regressing. His 18th birthday has long passed, he and Tony have been dating for months, and just a few weeks ago, Peter moved in with Tony. That is when Peter started to regress again, but it isn’t manifesting in the way it used to. Before, Peter would just go nonverbal, or get overly shy and anxious, often accompanied with tears and requiring cuddles and a nap to snap out of it.

This time, it’s not going away with some comfort or sleep, and the behavior is… more complicated.

Peter has only regressed in one way that they can tell. He is still verbal; he is still emotionally well; he just… can’t seem to be able to stop wetting himself.

The first time was traumatic for him, standing up after finishing a movie with Tony and immediately soaking his sleep pants. He was mortified and couldn’t look Tony in the eye for hours, but eventually, with much reassurance on Tony’s part, he came back around and was able to live normally again. The next time, a few nights later, Peter wet the bed during a nightmare. Again he was absolutely horrified; his crying being what woke Tony up.

The issue persists for weeks, and even though Tony insists Peter needs to see a doctor about it, Peter refuses. He’s almost 19, he shouldn’t be having this problem. They finally agree that Peter has a month to try to get a handle on his toileting problem, and if he can’t, he must go to the doctor.

The added stress of a deadline only seems to exacerbate the problem. Peter goes from a couple of accidents a week to daily wettings, the anxiety he feels around potentially wetting himself only making him more likely to do so.

It has effectively killed their sex life. Not that Tony cares, he is more worried about why Peter is having such a difficult time with knowing when he needs to go, but it is clearly frustrating Peter. The boy doesn’t have the gall to suggest anything sex related at all, worried that Tony thinks he’s gross, or worse, that he will have an accident mid-sex. Sometimes, though, when Peter is overtired and cranky and emotionally raw from a difficult day, he crawls into Tony’s lap for cuddles. And once there, he can’t seem to restrain himself from rutting against Tony’s thigh like he’s some kind of needy teen.

This actually works for a while. Peter goes a few days without having sex, presumably not even getting himself off because he is so disgusted with himself, goes to Tony for comfort, and ends up spending in his underwear, all shaking thighs and raspy breaths. With the edge taken off, Peter can then go for the rest of the day without an accident, but ultimately either wets the bed that night, or has an accident the next morning.

Of course, when Peter loses control of his bladder on the buildup to an orgasm a couple weeks later, he no longer feels welcome or worthy to sit in Tony’s lap at all anymore, much less allow himself to reach an orgasm there. With one more stressor added to the list and his only known coping mechanism gone, Peter goes almost completely incontinent with his urine.

Something has to give, and Tony finally suggests that Peter wear diapers. He tries to bring it up gently, to suggest it without crushing Peter’s self-esteem, but nothing can really soften the blow. Tony leaves the pack of diapers in the bathroom just in case, and later that day finds them gone.

Today, the day after the suggestion, Tony wakes up to one problem pacified, but a new one created. Peter is wearing a diaper, so that eliminates the worry of Peter’s wettings being so obvious and embarrassing, which will hopefully ease some of Peter’s anxiety. But…

“Pete?” Tony mumbles, petting his fingers through Peter’s hair. Peter has his thumb jammed in his mouth, looking up at him lazily.

“Hmmm?” Peter hums, blinking slowly.

“Everything alright?”

“M’fine, daddy.”

Tony’s mouth falls open, staring at Peter as if it will suddenly make this make sense.

“Hungry.” Peter murmurs, tugging at Tony’s t-shirt and frowning.

“Let’s… let’s get you something to eat, then.” Tony says slowly, standing up and signaling Peter to follow. A tangle of thin limbs comes rolling to the edge of the bed, and Tony looks away sharply when the sight of Peter in a diaper and an oversized t-shirt has his face going hot.

It isn’t long before Peter is stuffing his face with food, kicking his feet happily at his place at the table. “Thank you, daddy.”

“You’re welcome…” Tony says, sitting in the chair directly next to Peter. “Do you know who I am?”

Peter snorts. “Yeah, silly. You’re Tony.”

“Right.” Tony says. “But I’m not your daddy.”

Giggling, Peter nods. “I know, but you treat me so nice, and feed me good food, and take such good care of me. It’s like you’re my daddy, so I wanna call you daddy!”

Tony nods slowly. “Alright.” He murmurs, figuring that this can’t get too weird as long as Peter understands that he, his boyfriend, isn’t actually his father.

After breakfast, Peter wants to watch TV, a ritual they have followed since Peter moved in. They sit together on the couch watching some throw away romcom, when Tony notices Peter catch a chill out of the corner of his eye. He has come to recognize this as the only warning that Peter is about to lose control of his bladder in an immediate fashion, with absolutely nothing that Peter can do about it.

Peter’s body flexes against the sudden urge to pee, and as quickly as it came, it passes. The sound of urine streaming out of him and into his diaper feels deafeningly loud, and Peter’s face flushes as his diaper expands with the liquid.

Tony prepares himself to comfort Peter, to ignore the incident entirely, anything he needs to do to make Peter more comfortable. He expects Peter to cry, or maybe scurry away to change himself after he finishes. Instead, the trickling stops, and Peter… sighs. A small noise of relief before he relaxes further into the couch and Tony swallows against the way his stomach twists. He’s not disgusted, or even very uncomfortable. Which is the problem.

“Hey, Pete.” Tony says gently. “If you, ah, have an accident, you need to put on a new one of those.”

“Oh.” Peter says, looking down at himself. “Okay!”

Tony, while very uncomfortable with how comfortable he is with Peter wetting a diaper right beside him, is happy at how well it went over. This is the first time Peter’s age regression has seemed to actually help instead of hurt.

At bedtime, Tony tries to be proactive, encouraging Peter use the bathroom before bed.

“But that’s what I have the diapers for!” Peter protests, flopping down in bed.

“No,” Tony says, firm but kind. “The diapers are for accidents, if you can’t hold it. If you feel like you need to pee and you can make it, you need to use the toilet.”

“Oh.” Peter says quietly. “I piddled in the diapers a few times today. I’m sorry, daddy.”

Tony blushes. Since when does Peter say ‘piddle’? Since when does it make Tony feel hot all over? Tony swallows, trying to collect himself. “It’s okay; just… try to use the toilet whenever you can, okay?”

“Okay!” Peter chirps, crawling off the bed and walking past Tony into the bathroom. He approaches the toilet apprehensively, peeking down in the bowl before he calls out, “Daddy?”

Tony pokes his head in, smiling supportively, if not a little nervous. “Yes?”

“Can you… help me? I don’t wanna miss…”

“Okay…” Tony says softly, stepping in behind Peter. He’s touched Peter’s penis so many times before, what makes now any different? Other than the drastically different context?

Peter watches Tony carefully tug down the front of the diaper, pull his penis out, and aim him at the bowl. The natural impulse hits him, and soon the trickling of water on water can be heard. Peter looks back at Tony, grinning. “Am I doing good?”

“Very good.” Tony says, Peter’s genuine happiness tugging at the corners of Tony’s lips. Peter finishes, and Tony shakes Peter’s member a few times, milking out anything remaining just as he would himself.

“Mmm,” Peter hums, looking down at Tony’s hands. “I love how it feels when you touch me like that, daddy.”

Tony vehemently ignores the definite twitch of his cock at the remark. “I’m glad, Petey. Cmon, bed time.”

The makeshift solution comes just in time for a social event that Tony has to attend the next day, one that Peter is expected to join as well.

The event itself goes off without a hitch. Peter isn’t expected to speak, only to smile and look sweet, which he does perfectly. Tony is sure to give Peter plenty of potty breaks, round the clock, just to be sure there are no surprises.

In the backseat on the way home is when problems arise. They have no sooner left the venue than Peter gives Tony a deer in headlights stare, not nearly quiet enough when he says, “I need to piddle, right now.”

Tony looks in the rear view mirror and sees Happy staring back at him, brows raised.

“You’re gonna have to hold it, kid, nowhere to stop for another ten minutes.”

Tony slaps the switch to raise the partition when Peter immediately starts to bawl, both of his hands shooting down to his lap. As soon as he is sure that Happy can’t hear or see them, Tony says soothingly, “Hey, it’s okay, you can use the diaper.”

Peter shakes his head, big tears dripping onto his cheeks. “But you said it’s only for accidents!”

“Well, this is an emergency, which is just as good of a reason as an accident.” Tony assures, petting Peter’s shoulder. The boy’s clear discomfort makes Tony feel like his insides are about to turn out. “Go ahead, and when we get home you can use the toilet like you should.”

Peter nibbles at the inside of his lip, debating whether or not he can hold it. Tony’s house isn’t far away; he thinks he might could-

A sudden, harsh bump has Peter whimpering and squeezing at his crotch. Tony maintains eye contact, his chest tightening when Peter’s eyes go glossy and his visible discomfort slowly fades away. Tony dares a peek at Peter’s lap, watching his diaper expand with Peter’s fluids. Tony only tears his eyes away to smile at Peter reassuringly.

Peter huffs quietly, frowning at Tony. “I’m sorry, daddy.”

“It’s okay, sweetheart.” Tony says as evenly as he can muster. “All you need is more practice.”

Thankfully, due to the nature of the problem, Peter has plenty of chances to practice. Tony has a rotation where Peter tries to pee once an hour, and any time he feels like it otherwise. Other than his incident in the car, which Tony insists doesn’t count, Peter makes it the whole day without an accident.

“Are you proud of me, daddy?” Peter asks in the shower that night, watching Tony wash his hair.

“So proud, love.” Tony says. The weirdness of Peter calling him ‘daddy’ has worn off pretty quickly, in light of other, more personally conflicting issues for Tony.

“Do you ever have accidents?” Peter asks, voice low.

Tony rinses conditioner out of his hair and tries to remember the last time he wet himself. Considering that he had been blackout drunk and in his 20’s at the time, Tony decides not to mention that when he says, “I used to, a few times.”

“Did it… feel good?”

Tony avoids eye contact, clearing his throat. “I didn’t like it very much, it made everything cold and my pants were hard to get off because they were wet.”

“That’s not a problem with the diapers.” Peter says helpfully. “It stays really warm, and they’re easy to take off ‘cause of the tabs.”

Despite his better judgment, Tony asks, “Does it feel good?”

“It feels… really good.” Peter says, smiling shyly. “Yesterday I would lie on my tummy on the bed, cross my legs and jiggle my butt after piddling and it felt so good. But then I’d get hot all over and my tummy got all tingly and my penis got all full so I had to stop…”

Tony notices Peter’s erection before he does, debating whether or not it’s okay to give his boyfriend an orgasm if he is currently in a different headspace. He decides no, that he should leave well enough alone, and moves from under the stream of water to allow Peter to bathe.

The next morning, when Tony wakes up to find Peter face down on the mattress, grinding his hips sloppily, it’s not as easy to talk himself out of giving him a hand. Literally. “Hey, Pete?”

Peter startles and looks at Tony with dewy eyes. “Daddyyy… it feels so full… I need to piddle but I can’t when it’s so full…”

“Do you want me to help you?” Tony asks softly, instructing Peter onto his knees upon receiving an affirmative nod. He peels back one of the tabs on Peter’s diaper and pulls it open, freeing Peter’s erection. Tony smiles. “You stayed dry all night, sweetie.”

Peter would have responded, but Tony’s hand is holding him so well, and the way it feels running up and down the sensitive flesh has Peter huffing urgent breaths in a hurry. “It feels- it feels like I’m gonna piddle on you!”

“You won’t.” Tony assures, making sure to keep his movements steady. “Just try to keep thinking about how good it feels, and tell me if you want me to stop, okay?”

“Uh-huh…!” Peter keens, his hips stuttering and keeping poor time with Tony’s hand. “Oh, daddy!”

Tony is unsurprised when Peter ejaculates, gushes of white fluid dribbling over his hand. He is much more surprised by the stream of urine that follows directly after, raining down Tony’s forearm and onto the bed. Tony hastily yanks Peter’s diaper over the head of his penis, holding him in place as he relieves himself. He can feel the way heat flushes through the material and fills his hand where he is holding it, and he tries not to think about how hard he is right now, or how much he’d like to add his own come to the mess.

Peter is currently too blissed out to be embarrassed that he peed on his boyfriend, and spends the next 30 minutes of changing the sheets and showering raving about how good that felt.

The next few days actually sees some progress. They have found that Peter definitely has to pee every time he wakes up and finishes eating, and he usually needs to go after an orgasm. Otherwise Tony simply reminds him often, encouraging him to try to go even it only feels like he needs to pee a tiny bit.

They’ve been practicing holding it, starting in the shower, followed by just being in the bathroom, then Tony’s room, then the rest of the house. After a long week of constant vigilance, Peter has only had a few accidents, and he is mostly charge of his own toileting schedule. Tony even taught him how to aim, meaning he can do it all by himself, with Tony only reminding him in the morning, after breakfast, and after he comes.

The problem with that is that Peter has really grown used to the company when he goes, even if it is only Tony standing in the doorway. Going to the bathroom all alone is boring and a little lonely, and the thought of having to stop being around Tony for any amount of time just to get liquid out of his body starts to feel like torture. He starts to get creative with ways to avoid having to leave Tony, or at the very least without having to go far.

His personal favorite is between the couch cushions. With Tony sitting on the couch watching TV and Peter with his head in his lap, it’s easy to tug down the front of his diaper, push himself as deep between the cushions as it will go, and just let go. The first time was the scariest because he didn’t know if it would make much noise, but it doesn’t, and he’s able to relieve himself without leaving Tony and without wetting his diaper.

Sometimes that isn’t an option, because if he isn’t already lying down, it’s not as easy without being caught. When he has to get up, he opts for carefully opening the coat closet just inside the hallway off of the living room. Peter can see Tony, but Tony can’t see him, giving him the opportunity to empty his bladder on the carpet beneath the coats.

The houseplants that are placed in the hallway seem like an obvious choice, and Peter thinks it is the one that he is least likely to be caught using. They are further down the hallway than the closet, so not as close as he would like them to be, but when he crouches a bit and starts to go in the dirt surrounding the plant, it is practically silent. The only bit of splashing that can be heard is so quiet that only Peter would notice. He has to stop using them, though, because before long they die and Tony gets rid of them.

His last ditch is to just hold it for as long as possible, but Tony usually notices his squirming and grabbing himself and tells him to use the bathroom. Peter starts to get better at not showing when he has to go until the last minute. He often waits for the end of tv shows, when Tony is likely to get up for a bathroom break himself, and follows him to the bathroom then.

But sometimes, like right now, they watch a movie. Peter can’t hold it for the length of a movie, he doesn’t want to stop, he doesn’t want to leave Tony, and Tony never seems to have to go in the middle of a movie. Peter swallows where he sits, the pain in his bladder mounting. He considers going to the closet, but Tony said something about a weird smell in there yesterday, and Peter told himself to wait a while before using it again. With the plants gone and his urgency preventing him from thinking up something new, Peter says softly, “Can I lay down, daddy?”

“Sure.” Tony says, scooting to sit beside the arm of the couch and giving Peter room to stretch out.

“Thank you.” Peter says quickly, wincing at how full he feels as he lies down. He does his best to wait for a few minutes, but he simply can’t hold it anymore, the new position proving to give him less control.

Tony notices Peter squirming as soon as he lies down, and when Peter continues to be restless, he peeks at him to check if he needs to be reminded to use the toilet. Tony’s mouth nearly falls open when his eyes land on Peter’s shaky hands pulling down the front of his diaper. Once his penis is out he immediately pees a little, splattering messily on the cushion, but Peter hastily shoves himself between the cushions. It’s not very deep, just his head making it in before he loses what little control he had.

Peter knows that he isn’t as deep as he normally is, but he has to go so badly that it doesn’t really occur to him that being too shallowly inserted might cause a problem. He closes his eyes and tries not to shudder with relief when he allows his muscles to relax and he feels the pressure in his bladder start to ease.

Tony watches Peter’s urine build up and spill down the crack of the couch, seeping over the surface of the cushions and making them grotesquely wet. The sound of liquid hitting the floor catches his attention, and he realizes there is so much that it has spilled over the front of the couch, too. “Peter?”

Peter, halfway done and deeply relaxed, startles at Tony’s voice. All at once he realizes what is happening, and he immediately pulls his penis out from between the cushions to try and put it back in his diaper. Because he is on his stomach and already so far gone, he couldn’t stop the stream if he wanted to, and he can’t really get himself back into his diaper because he is now lying on top of it. Peter makes a small sound of panic as he soaks the top of the cushions, and all he can really do is push himself back into the couch and let himself finish, which he does.

Tony tries to stay calm. He’s not mad, or disappointed, or disgusted. When Peter finishes and he watches the boy sheepishly tuck his penis back into his diaper, arousal spikes so hard in Tony’s stomach that it feels hard to breathe. He clears his throat, finally saying, “What was that about, Petey?”

Peter breaks down into tears, his cheeks hot with shame. He explains what happened, and confesses to his other hiding places, and apologizes. “I’m so sorry daddy, I’m so sorry!”

“Hey, shh,” Tony soothes. “It’s alright, it’s alright. But you can’t…” Tony pauses, looking at the damage done to his expensive couch. He hates the way it has his heart pounding. “You can’t keep doing this. I will come with you to the bathroom if you don’t like being alone, okay?”

Peter sniffles and nods. “Okay…” His eyes land in Tony’s lap, and Peter smiles shyly past his still falling tears. “Daddy, you’re full.”

Fresh shame dampens Tony a bit, and he gently blocks Peter’s hands from touching him through his jeans. “Ah, yeah, daddy does that sometimes. I will get rid of it later.” He knows it’s a lie when he says it, he hasn’t gotten himself off in weeks out of sympathy for Peter. But the thought of Peter touching his cock, in a diaper, on a couch soaked in his piss, has Tony’s head feeling way too swimmy for him to be comfortable with.

“But you take such good care of me, daddy.” Peter pouts. “You make me feel so good when I’m full, and then I’m empty, and I’m sleepy and you let me sleep, I wanna do that for you, too.”

Tony swallows. For some reason it had felt a little bit different when he gave Peter relief. At night, just before bed, when he brings Peter over the edge and then helps him remember to use the bathroom before bed, it feels like the right thing to do. Charitable, even. So what if he has to ignore his own burning arousal, barely able to shoo away the fantasies of pinning Peter to bed and fucking him until he soaks them both.

“Daddy?”

“No.” Tony says softly, patting Peter’s hands. “I’m fine, you make me feel good already.” Tony hadn’t expected the remark to be so on the nose, but it seems to pacify Peter for the moment. “Let’s clean up this mess, okay?”

That night, as has become routine, Tony sits against the headboard. Peter sits between his legs, naked with his back to Tony’s chest, absolutely reeling with pleasure.

“Daddy, daddy!” Peter chants, his hips canting sloppily. It feels so good, Peter goes completely offline as long as Tony is touching him. It’s never for long, because Peter always feels an uncontrollable pressure building in his belly within minutes of starting. It takes away his ability to think, to speak, to even move, his head falling back onto Tony’s shoulder as the swelling feeling reaches a crescendo. He squeals and his feet kick against the overwhelming pleasure, and he is spilling hot, white fluid over his own stomach.

“Good boy.” Tony coos under his breath. “Alright, let’s have you pee and get cleaned up, hm?”

“You’re full again, daddy.” Peter says, wiggling his butt against the outline of Tony’s cock.

Tony bites back the noise his body wants to make, grabbing Peter’s hips to hold him still. “Yeah, but it’s okay, I can deal with that later. Right now all I want to do is make sure you are all clean and ready for bed, okay?”

Tony didn’t deal with it later. He just gets Peter all tucked into bed, and there they fall asleep together.

Peter startles awake in the middle of the night, pressure in his bladder pulling him out of his dreams. He rolls over to wake Tony up and have the man accompany him, but is silent when big hands feel over his waist and down his butt.

“So fucking sexy, Peter.” Tony mumbles, pulling Peter’s body flush against his.

Peter squints through the dark, realizing that Tony’s eyes are still closed. Peter feels himself getting full at the way Tony is whispering in his ear, and he squeaks when Tony grinds forward into him.

“M’gonna fuck you ‘till you can’t hold it.” Tony rasps, his hips seeking the warmth of his boyfriend in front of him. “Get me all wet, nnf…”

“Daddy?” Peter asks quietly, squirming against his need to pee. Tony is squeezing him too tightly, he feels like he could start leaking.

Tony startles awake, taking a moment to survey the pretty face looking back at him, twisted up in a familiar discomfort. “What’s..?” It takes another few seconds to recognize the hot pressure behind his cock, and then that he has Peter crushed into his front. “Oh. Sorry, Petey, daddy shouldn’t have done that.” Tony’s voice is raspy with sleep, and he barely realizes that he’s used the title on himself.

Peter tips his hips forward, heat blossoming over his skin at how clearly he feels Tony’s erection through his diaper and the thin material of Tony’s underwear. “No, I want you to, it feels… it feels really good.”

Tony wets his lips. His cock flares at the idea of dry humping Peter into a quivering mess, and he’s having a hard time remembering why the hell he hasn’t yet. “Alright sweetie, c’mere.”

Peter gasps when Tony rolls on top of him, resting heavily between his legs. He is suddenly reminded in an urgent fashion that he needs to pee, and he whimpers when Tony thrusts into him. “I- daddy I need to go.”

“Go where?” Tony mumbles as he presses his face into Peter’s neck, smelling of his sweet skin before kissing it.

“I need to _go_.” Peter says, a hint of shame in his voice.

Tony hums, sitting back on his haunches and looking down at Peter. His t-shirt rests above his belly button, leaving his diaper in plain sight. Tony turns on the lamp beside the bed to see him better and pets his hand over Peter’s crotch, feeling Peter’s erection beneath. “We can stop so you can go, love.”

Jaw slack, Peter keens at Tony’s touch. “I don’t wanna get up… I could just… piddle a little bit in my diaper, and then do the rest in the toilet after?”

“Oh god,” Tony murmurs, moving his hand to rest over Peter’s cock head. “That sounds like a great idea, sweetheart. Go ahead.” Tony feels heat spreading under his hand immediately, and he groans at the pressure of arousal in his groin. “There you go, that’s a good boy. Not too much, hear me? Don’t want to get your diaper too full, do we?”

Peter shakes his head, focusing on keeping the stream of urine slow enough that he can stop when he needs to. He allows just enough to trickle out that it takes the edge off, squeezing his muscles to bring the stream to a halt. “All done, daddy.”

“Such a good boy for me.” Tony practically growls, gripping his fingers around the squashy material of Peter’s diaper. “Let me get this wet thing off of you.”

Sparks go off in Peter’s stomach when Tony’s warm fingers tease at the waistband. He watches Tony pull off each of the tabs and peel back the front of his diaper, exposing his damp cock.

“So fucking pretty.” Tony murmurs, petting his fingers over Peter’s cock. He easily removes his own underwear and tosses them onto the floor, sitting against the headboard. “Here, baby.”

Peter looks at Tony skeptically, easing himself with his back to Tony’s chest. “I thought you were gonna-?” Peter squeaks when Tony easily turns him around and pulls him to straddle his hips. Peter’s cock stands right next to Tony’s, full and hot. Peter’s mouth falls open when Tony’s hand wraps around them both. “Oh, oh daddy..!”

“I hear you, baby.” Tony says absently, watching the way Peter’s hips squirm helplessly to try and make his hand move faster. Tony doesn’t bend, moving his hand slowly, firmly up and down the heated skin. He holds this pace for no less than 10 minutes, going as far as to go even slower if Peter gets wound too tight. Tony is waiting for what he knows is inevitable, watching Peter’s face go from completely blissed out to quirked with discomfort, his cock leaking for the way Peter suddenly tries to bring his knees together. Tony gets in Peter’s head space, huffing hotly in his ear, “Everything alright, baby boy?”

“I- daddy I need to piddle.” Peter whimpers, his hands squeezing in Tony’s shirt. “I need to go right now.”

“Go ahead, sugar.” Tony drawls. His hand that isn’t occupied with their cocks grabs Peter by the hip when the boy tries to back away.

“Daddyyy!” Peter whines, bouncing urgently. “I’m gonna- I need to go!”

Tony tuts when Peter hurriedly reaches back for his discarded diaper, but allows him to grab it. “You don’t need that.”

Peter uses it anyway, shaking hands pushing the absorbent material on top of his cock, and subsequently Tony’s, too. Peter bites his lip and tries to relax his muscles, whimpering when only a small dribble of pee is actually able to come out. “Daddy I can’t do it when I’m this full!”

Tony moves his hand faster, the new, wet heat added to the inside of the material making his mouth go dry. “Let me empty you, sweetheart.”

It only takes a few seconds more, the new speed and the heat of Tony’s cock against his and the urgency to empty his bladder only pushing him closer. Peter’s thin, insistent noises taper into silence when he reaches the end of his rope and his hips jar against Tony’s hand as he comes.

Tony groans when Peter’s release dribbles down his hand, and he almost loses it himself when it is immediately followed by hot liquid.

Peter whimpers after a moment, his cheeks going red. “It’s full, it won’t-“

Tony already knows, watching the overused material drip with Peter’s urine, refusing to take any more. “How much is left, baby?”

“A lot,” Peter says, straining to tighten his pelvic muscles and giving Tony a panicked look. “And I can’t make it stop! It’s going to get on the bed, daddy!

“Hey,” Tony soothes. “Don’t worry, look.” Tony points at his shirt. “My shirt is nice and dry. Use it, and it won’t get on the bed, okay?”

Peter hesitates, but he’s fresh out of options. He nods, carefully pulling his diaper away and tossing it to the side.

“There you go.” Tony murmurs, encouraging Peter to scoot up his body to sit on his stomach. Tony continues to stoke himself, looking at Peter’s cock as dribbles of pee wet his shirt. Peter is clearly trying really hard to hold it. “Let go, Petey, it’s okay, you’re okay.”

Peter nods timidly, relaxing and allowing his body to relieve itself over Tony’s chest. Tony’s gray t-shirt goes black as it absorbs Peter’s urine.

The room is silent but for the lewd sound of Peter’s piss leaving his body, the force at which it is expelled a testimony to how badly Peter had to go. Tony swallows as wet heat dribbles down his sides, over his shoulders. He is close anyway, but when the stream dwindles to a dribble and Peter fucking _sighs_ , relief heavy in his breath, Tony loses it. He comes hard, painting Peter’s back with his release. Tony sags into the bed with a harsh sigh, his eyes slipping closed.

Neither of them planned on falling asleep there, but they did. Tony wakes up the next morning to Peter squirming on top of him.

“You need to go?”

“Mm-hm…”

“Go ahead.”

“Your shirt’s still wet.”

“I don’t mind.”

“I… I like using the diaper.” Peter admits quietly.

“Oh.” Tony says. “Well… you only have a few days before we need to take you to the doctor to see if everything is okay. Do you want to just… use the diapers until then?”

Peter wiggles his hips, his discomfort clear. “Please?”

“Sure.” Tony says, gently lifting Peter off of himself and disappearing into the bathroom, only to return with a fresh diaper. By the time he makes it to the bed Peter is on his knees, holding himself in his hand. “Do you want me to put it on you?”

Peter shakes his head. “I need to go _now_. Can you just…” Peter motions with his head for Tony to place the diaper between his legs, and directs his penis downward. As soon as he lets go of himself it is flooding out, hissing quietly. He fills the diaper to its limit, sends Tony a sheepish smile, and they move on to a shower.

After last night, Tony tries to allow himself to be comfortable with the fact that he is utterly, helplessly turned on by Peter wetting himself. Once he doesn’t feel so bad about it, he decides that now is the time to enjoy it, because it’s unlikely that Peter will want to wet himself on purpose after they fix the problem.

It starts once they are out of the shower and Peter has a fresh diaper on. They go downstairs for breakfast, where they eat and plan their day. Tony has to attend a meeting at Stark Industries. He offers to let Peter stay home, but Peter insists that he come. Tony doesn’t remind him to use the bathroom before they leave.

The realization hits Peter almost as soon as they drive away, whispering harshly to Tony, “I need to piddle, did you bring more diapers?”

“No baby.” Tony says softly.

Peter whimpers, looking at the back of Happy’s head. He debates just asking him to pull over. The highway isn’t… _that_ busy… Peter frowns and accepts that the idea won’t work, looking at Tony desperately.

Tony points at Peter’s floorboard, leaning in to whisper, “If you’re quiet, he might not notice.”

Peter blushes, but he’s already pulling at the button of his pants. He aims downward, the muted trickle sounding entirely too loud on the plastic. Happy doesn’t notice, though, and Peter is hurriedly putting himself away and buttoning his pants as soon as he is finished.

“Feel better?” Tony asks sweetly, discreetly adjusting himself in his pants.

Peter nods sheepishly. “Yeah, a lot better.”

Later, in the middle of a meeting, after hours of talking, and sipping water, and waiting, Peter squeezes Tony’s hand to get his attention.

Tony, not even listening to what the speaker has to say, tips his head to listen to Peter without alerting anyone.

“Am I allowed to leave?”

“Not until he’s done talking.” Tony’s voice is flat. He seems just as dismayed that he isn’t allowed to leave, either, and doesn’t immediately realize what Peter is implying.

“Daddy, I gotta…”

Tony has to catch himself from snapping his head to look at Peter. Instead he squeezes Peter’s hand supportively, and moves his hand to lay over Peter’s crotch.

Peter holds out for as long as he can, which only ends up being a few minutes. He looks down when his muscles spasm and he is emptying into his diaper, trying hard not to squirm or make noise.

Tony is made impossibly hard by the way Peter’s lap gets hot and expands under his hand. He strains his ears to hear any sound it might make, but it is practically silent.

By the time the meeting finally ends, Peter doesn’t really want to leave his seat. He waits until everyone leaves, trying to be as casual as possible, finally looking at Tony and whimpering, “I think it will leak if I walk!”

Tony wets his lips. “Sounds like you need to take it off.”

Which is just what happens, Peter wearing nothing under his pants and a blush on his cheeks when they leave the room. Tony smirks beside him, his arm wrapped easily around his shoulders.

Peter is happy to be home and in a clean diaper, practically asleep on the couch after dinner. It is cushy and brand new, Tony had it installed while they were away, to replace the one he… used.

Tony runs his fingers through Peter’s hair, checking emails on his phone while Peter dozes. He pets his hand gently over Peter’s lower stomach, tugging up the hem of his shirt and carefully pressing his fingers into the waistband of Peter’s diaper. Peter sighs softly in his lap, his hips pushing into the warmth of Tony’s hand.

“Feels good, daddy.” Peter mumbles, rutting lazily into Tony’s palm. He gasps softly when Tony wraps his fingers around his growing cock, but doesn’t move. Peter realizes that he still has to keep going, and eagerly thrusts his hips. But he is so tired, so close to drifting off, that he loses steam before he can finish.

“That all you got?” Tony asks, faux disappointed.

“Mm-hm.” Peter hums. “M’sleepy.”

“Let’s get you in bed then, sweetie.”

Peter stands and follows Tony, adjusting himself in his diaper. His penis, growing softer, sits straight up in Peter’s pelvis. He doesn’t even notice that the head is peeking out of the top, and thanks to his baggy shirt, neither does Tony.

Later that night, cuddled into Tony’s side, Peter blinks awake. He feels hot all over, the squeeze of his cock against Tony thigh feeling stunningly good. He rolls his hips, gasping softly.

Tony only wakes up when Peter is almost finished, huffing little moans against his shoulder while his hips stutter sloppily. He smiles when Peter croaks out a tiny shout, driving his hips forward once, twice, and finally relaxing into the bed.

Peter is barely lucid when his body alerts him that he needs to make, right now. Knowing that he is safely in a diaper and in his own bed, Peter just hums contently, allowing his body to do what it needs so that he can go back to sleep.

Tony hears the unusually loud hiss of Peter’s urine immediately, and soon after feels the wet heat spreading over his thigh. As much as he would like to pin Peter to the bed and ruin him, he decides to just wait for Peter to finish and doze back off. He can take care of himself then.

Peter shudders as the final drops soak into Tony’s underwear, and he is back to sleep within seconds.

“Fuck.” Tony breathes, pushing his hand into his soaked underwear to stoke his cock.

The week ends, and Peter finally allows Tony to take him to see a urologist. It turns out, Peter just needed a good therapist, a bit of medication, and reassurance that bathroom accidents as an adult are nothing to be ashamed of. After a few weeks of work on everyone’s part, Peter is entirely in control of his bladder again.

They keep the diapers around, though. There are nights where both of them feel like Peter should wear one, even though he no longer needs them.


End file.
